f201ae2356
Impact: use deeper function tracing depth safely Some tests showed that function return tracing needed a more deeper depth of function calls. But it could be unsafe to store these return addresses to the stack. So these arrays will now be allocated dynamically into task_struct of current only when the tracer is activated. Typical scheme when tracer is activated: - allocate a return stack for each task in global list. - fork: allocate the return stack for the newly created task - exit: free return stack of current - idle init: same as fork I chose a default depth of 50. I don't have overruns anymore. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
57 lines
1.2 KiB
C
57 lines
1.2 KiB
C
#ifndef _ASM_X86_FTRACE_H
|
|
#define _ASM_X86_FTRACE_H
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
#define MCOUNT_ADDR ((long)(mcount))
|
|
#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
|
|
|
|
#ifndef __ASSEMBLY__
|
|
extern void mcount(void);
|
|
|
|
static inline unsigned long ftrace_call_adjust(unsigned long addr)
|
|
{
|
|
/*
|
|
* call mcount is "e8 <4 byte offset>"
|
|
* The addr points to the 4 byte offset and the caller of this
|
|
* function wants the pointer to e8. Simply subtract one.
|
|
*/
|
|
return addr - 1;
|
|
}
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
struct dyn_arch_ftrace {
|
|
/* No extra data needed for x86 */
|
|
};
|
|
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */
|
|
#endif /* __ASSEMBLY__ */
|
|
#endif /* CONFIG_FUNCTION_TRACER */
|
|
|
|
#ifdef CONFIG_FUNCTION_RET_TRACER
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
/*
|
|
* Stack of return addresses for functions
|
|
* of a thread.
|
|
* Used in struct thread_info
|
|
*/
|
|
struct ftrace_ret_stack {
|
|
unsigned long ret;
|
|
unsigned long func;
|
|
unsigned long long calltime;
|
|
};
|
|
|
|
/*
|
|
* Primary handler of a function return.
|
|
* It relays on ftrace_return_to_handler.
|
|
* Defined in entry32.S
|
|
*/
|
|
extern void return_to_handler(void);
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
#endif /* CONFIG_FUNCTION_RET_TRACER */
|
|
|
|
#endif /* _ASM_X86_FTRACE_H */
|